Heat-resistant members such as earthenware, glass, and ceramics have been decorated with the use of, for example, an underglaze color that paints these materials underneath a high-temperature glaze (glaze). The underglaze color is a paint for forming a colored oxide coating, and is typically emulsified with a glue from fats of animals (such as deer, and rabbits) to improve glaze viscosity. The underglaze color paint is heated to vitrify at about 1000° C. It has become common to use an inkjet printer for printing image on various media. For example, there are studies to decorate glass or other such products by printing with an UV ink (UV curable ink) according to the inkjet scheme.